The present application relates to cores for dynamo-electric machines and methods for manufacturing such cores, and more particularly to those of brushless motors.
The stator core of a typical dynamo-electric machine has a lamination stack and insulation end boards. Coils of wire are wrapped around the stack and end boards. Coil leads, extending from the wire coils, are drawn and wrapped around respective terminal posts located at an axial end portion of the stator assembly. The terminal posts, in turn, are electrically connected to circuitry that generates commutation signals to cause rotation of a rotor assembly with respect to the stator.
In the prior art, terminal posts are typically fixed directly to the insulation end board adjacent the wire coils, and are not movable with respect to the insulation end board of wire coils. The known terminal post configuration presents several disadvantages in view of conflicting design considerations. For example, the terminal posts must provide sufficient structural support at the anchoring point as well as adequate clearance for apparatus used in the manufacturing process.
Winding of the coils and wrapping of the leads around the terminal posts for a typical stator can be accomplished by a traditional flyer winder, which rotates about the stator to dispense the wire. When using a flyer winder, there should be a minimum axial clearance between the ends of the coils and the terminal posts to accommodate the path of the flyer and wire strand. Furthermore, the terminal posts must be sufficiently strong to withstand the loads from the winder during the wrapping of the leads around the terminal posts.
Subsequently, the leads are fused to the terminals, particularly if tang-type terminals are used. Sufficient axial clearance between the end of the coil and the terminal post may be necessary during the fusing operation to allow access for an electrode assembly. Once the leads have been fused to the terminals, the terminals must have sufficient structure to hold the lead in place.
The above requirements of clearance and strength produce a terminal configuration having increased axial length and terminal support structure. This is in conflict with another design consideration that teaches that the stator should be as compact as possible in the axial dimension to meet space constraints, for example. The prior art terminal posts designs, therefore, do not address this concern.
In view of the foregoing, it is an object of this invention to provide a stator design and method of manufacture which provides sufficient strength and access for manufacturing equipment.
It is a further object to provide a stator design and method of manufacture which results in compact overall dimensions.